Control line reducing hydraulic control system and control valve therefor

ABSTRACT

A control valve includes a housing, an inlet port at the housing, a device port at the housing, a valve port at the housing, and a spool disposed at the housing, the spool initially connecting the inlet port to the device port and subsequently to a pressure event connecting the inlet port to the valve port. An actuation system includes a plurality of control valves, each valve being addressable and conditionable to communicate with one of a device and another control valve, and a plurality of devices each in operable communication with one of the plurality of control valves.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional application 60/836,022filed Aug. 7, 2006, the entire contents of which are incorporated hereinby reference.

BACKGROUND

Hydraulic control of downhole systems has long been a trusted and thusubiquitous choice of well operators. Hydraulic control lines arerelatively small, are simple to operate and very reliably transmitpressure to distant locations where either the existence of pressure isused as a signal or a higher pressure fluid volume is used to actuate ashiftable device downhole.

In older well completions relatively little control was used in thedownhole environment and correspondingly few control lines were neededto extend back to the surface. In view of the relatively small number oflines, dealing with them with openings through packers (feed-throughpackers, etc.) and the like has always been accepted and functional. Aswellbore complexity has increased however with an ever-expanding needfor control related to improved production quality and quantity, agreater number of flow modifying structures (e.g. valves) and otherdownhole equipment has been placed downhole to enhance return oninvestment. With the additional devices downhole comes a requirement toprovide a control regime for such devices. While hydraulic control linesare still quite well favored as a control means, the multiplicity ofcontrollable devices causes the number of control lines required withtoday's technology to exceed the space available to run them. In manytypical completions today the number of control lines will equal thenumber of devices plus 1. With consideration of the possibility of 15000feet of wellbore having perhaps 40 valves or other controllable devices,it is easily imagined that the needed 41 control lines will havedifficulty fitting in the 9⅝ inch annulus around a completion string.

In view of the foregoing, the art would certainly welcome a means forreducing the number of control lines necessary to individually control amultiplicity of devices downhole.

SUMMARY

Disclosed herein is a control valve. The valve includes a housing, aninlet port at the housing, a device port at the housing, a valve port atthe housing, and a spool disposed at the housing, the spool initiallyconnecting the inlet port to the device port and subsequently to apressure event connecting the inlet port to the valve port.

Further disclosed herein is an actuation system. The actuation systemincludes a plurality of control valves, each valve being addressable andconditionable to communicate with one of a device and another controlvalve, and a plurality of devices each in operable communication withone of the plurality of control valves.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an embodiment of a control valve asdisclosed herein;

FIG. 2 is a schematic illustration of four control valves and fourhydraulically actuatable devices representing an embodiment of ahydraulic control system;

FIG. 3 is the illustration of FIG. 2 in a different position;

FIG. 4 is the illustration of FIG. 2 in another different position;

FIG. 5 is the illustration of FIG. 2 in another different position;

FIG. 6 is the illustration of FIG. 2 in another different position; and

FIG. 7 is the illustration of FIG. 2 in another different position.

DETAILED DESCRIPTION

Initially it is pointed out that while described embodiments of thecontrol valve and system hereof may be described in terms of downholeequipment or use, the hydraulic activation system can be applied to anyfield in which it would be advantageous to control multiple devices withonly three control lines.

Referring to FIG. 1, a control valve 10 is illustrated schematically.The valve 10 includes a housing 11 supporting a spool 12. Spool 12 isresponsive to pressure at an inlet port 14 both in terms of thetransmission of hydraulic fluid pressure and in terms of the directactivation of the spool itself. The control valve 10 acts to eitherprovide hydraulic pressure to a device or to pass hydraulic pressure toa next control valve in a series of two or more valves. It is to beunderstood however that the control valve herein can also be usedwithout a second or other number of valves. A single one of the controlvalves disclosed herein can be selected for use for any number ofapplications where a first and a second flow or pressure path isrequired or desired.

Effectuating the ability of the valve to provide the two communicationpaths (pressure or flow paths), the spool 12 is cyclable between twopositions. Movement from a first position to a second position happensautomatically upon a first application and release of pressure to thevalve either initially or after a reset and movement from the secondposition to the first position is achievable by application of pressureto a separate port of the control valve discussed further hereunder. Itis to be understood that automatic movement from the first to the secondposition can occur as already stated and can also occur simultaneouslywith the second pressure event after initial use or reset forapplications where it is desirable that the first communication path beleft connected until the second pressure event. Such, for example, maybe the case where fine adjustment is desired of the device being actuateand a back flow of fluid therethrough is efficacious of the desiredresult.

With respect to the illustrated embodiment and more specificallyreferring to FIG. 1, spool 12 upon a first application of hydraulicfluid pressure from a remote location (not shown) to inlet port 14 willtransmit that pressure through spool path 16 to a device port 18. Upon areduction of pressure at inlet port 14, spool 12 cycles to allow a fluidconnection capability therein to provide such connection through a spoolpath 20 between inlet port 14 and a valve port 22. It is important tonote that in this embodiment this cycle occurs only upon a very firstpressure and release or after a reset of the control valve 10.Subsequent application of hydraulic pressure from the remote location toinlet port 14 is directed through spool 12 to valve port 22, the spoolremaining in this second position until reset by application of pressureto a reset port 24 whereafter the next subsequent pressure event will betransmitted through spool path 16 to device port 18 again. The controlvalve 10 is selectably positionable between the two positions any numberof times simply by selecting which port to pressure-up on from theremote location.

Still referring to FIG. 1, it will be appreciated that the spool 12includes a plurality of seals 26, which in one embodiment are o-rings asillustrated. Each o-ring is positioned to be located on one side or theother of a fluid flow path to enable the flow paths to hold pressure.One of ordinary skill in the art will appreciate this from the figure.Further included on spool are recesses 28 and 30. The recesses arecarefully positioned relative to each other and relative to pistonassemblies R and Q so that desired operation of the control valve can beaccomplished. Recesses 28 and 30 must be positioned so that once recess28 becomes disengaged with assembly R, the spool 12, under urging fromcompression spring 32, moves in the direction depicted on the left ofthe figure. The spool movement left will be limited by assembly Q but issufficient to prevent reengagement with assembly R until reset of thecontrol valve 10.

Addressing Assemblies R and Q in detail, each assembly is exposable topressure at inlet port 14 as illustrated in the figure through R branch34 and Q branch 36, respectively. It will be appreciated from the figurethat the assemblies are pressure actuated at axially different ends. Alock shuttle 38 is disposed between the assemblies R and Q andconfigured for selective engagement therewith.

Upon application of pressure to inlet 14, branch 34 and branch 36transmit pressure, and volume to the assemblies R and Q. When pressureis applied to assembly R, piston 40 moves against the bias of spring 42toward the upper margin of the figure. This movement disengages pin 44from recess 28. Simultaneously, piston 46 of assembly Q moves toward thebottom margin of the figure against the bias of spring 48 to engage pin50 with recess 30. It is to be appreciated that the spring rates betweenspring 42 and spring 48 are different. Spring 48 is of a lesser springrate to ensure that the pin 50 engages recess 30 prior to pin 44releasing recess 28. This, as is apparent from the foregoing discussionand drawing figure is necessary to prevent the spool 12 moving to thesecond position prematurely. As was noted earlier, the positioning ofrecesses 28 and 30, prevent the reengagement of pin 44 with recess 28once released from recess 28 (until reset). The shuttle 38 automaticallymoves into assembly Q upon the simultaneous movement of the assembliesand is locked there. Shuttle 38 remains locked in assembly Q untilpressure is bled from branches 34 and 36. In order for the shuttle tounlock from assembly Q, assembly R must move to a position where theshuttle can move thereinto. This occurs when the pin 44 rests on anoutside surface 52 of spool 12, which readies the spool 12 for its shiftto the second position under the impetus of spring 32. As soon as thepin 44 reaches the outside surface 52 the pin 44 itself is urged againsta spring 45 within a cavity 47 of piston 40, the shuttle is moveableinto assembly R thereby releasing assembly Q. Because assembly Q isbiased by spring 48, assembly Q moves to a position of disengagementwith recess 30. Once pin 50 is disengaged with recess 30, and recallingthat pin 44 is resting on surface 52 as opposed to being engaged withrecess 28, the spool is free to move leftwardly in the figure in orderto position the spool in the second position. Resetting of the controlvalve requires pressure at reset port 24 which urges spool 12 againstthe spring 32 until pin 44 reengages recess 28 under the bias of spring42. It will be appreciated that the engagement of shuttle 38 with piston40 is a loose fit to allow piston 40 and pin 44 to move into engagementwith recess 28 even when engaged with shuttle 38.

The control valve(s) 10 as described above enable hydraulic actuationand control of from one to many downhole devices while requiring onlythree control lines (illustrated as A, B and C in the drawings hereof)in any given position of the system and a number of control valves equalto the number of devices. The control valves may be a part of thedevices themselves or separate therefrom as desired.

Referring now to FIGS. 2-7 one embodiment of the hydraulic activationsystem is illustrated in various positions as pressure is cycled toeffectively present to the reader the functionality of the system. InFIG. 2, a first control valve 10 is in a position whereby hydraulicfluid pressure applied through control line A to port 14 a is sentthrough spool path 16 a device port 18 a and from there through flowindicator 60 to a device 100. The pressure up event may be used toactivate device 100 or may alternatively be used solely to cycle valve10 a. In the illustration, the device 100 is actuated to the openposition. Whether or not device 100 is activated, valve 10 a will cyclefrom the first opposition wherein inlet port 14 a is connected to deviceport 18 a to the second position wherein inlet port 14 a is connected tovalve port 22 a. If it is desired that this pressure up event activatesdevice 100, then control line C is to be open to a pressure lower thanthat applied to line A. If alternatively device 100 is not intended tobe activated by the particular pressure up event at line A, then line Cis to be capped or otherwise maintained at a pressure equal to that atline A to thereby hydraulically lock device 100 preventing activationthereof.

Following the first pressure up and release of line A, control valve 10automatically shifts to the second position. This is illustratedschematically in FIG. 3 where spool path 20 a is illustrated connectinginlet port 14 a to valve port 22 a. Another flow indicator 62illustrates the fluid path then provided from valve port 22 a to inletport 14 b in control valve 10 b.

Identically to the action just described in control valve 10 a, controlvalve 10 b is activated initially (or after reset) by a first pressureup of indicator 62. It will be understood that as first use of theentire system, or after reset, which occurs in all control valvessimultaneously, pressure at inlet port 14 b is achieved only bypressuring up twice on line A. Indeed the number of pressure events toactivate a particular control valve at initial use or after reset isequal to the number of control valves preceding the target valve plusone. Likewise, the first pressure up event experienced by each valvewill result in pressure at device port 16 while a second or subsequentpressure event experienced as each valve will be transmitted to valveport 22 and thus to the next valve in a series of valves. A series ofvalves may be as long as desired without detrimental effect untilfrictional forces incurred by the actuating fluid build to a degree thatpressure change becomes insufficient to operate devices or cycle thecontrol valves. With the use of a common ¼ inch control line and thecontrol valves as configured in FIG. 1, it is axiomatic that a greatnumber of valves may be used before friction imposes restriction asnoted.

When addressing control valve 10 b as illustrated in FIG. 3, activationor not of device 110 (illustrated as actuated open in the figure) isachievable through flow indicator 64 similarly to activation or not ofdevice 110 as noted above.

Upon a subsequent pressure event for control valve 10 b, pressure ispassed through spool port 20 b to valve port 22 b through another flowindicator 66 to inlet port 14 c of control valve 10 c which isillustrated as addressed in FIG. 4 (in FIG. 4 the device 120 isillustrated as not actuated and therefore left in the closed positionwhile the spool valve is cycled). The process described is repeated foras many valves as are in the series.

As will be appreciated from the foregoing, any or all of the devices100, 110, 120 or 130 can be selectively positioned as desired in theopen or closed position pursuant to the appropriate number of pressurecycles (1 plus the number of devices preceding the target device) andthe conditioning of line C to either permit pressure to exhausttherethrough or to not allow pressure to exhaust therethrough thusallowing actuation of the device or causing the device to remainhydrolocked in place, respectively.

Further to the selective actuation from a first position to a secondposition of the devices as disclosed above, the control valve(s) andsystem described herein also facilitate selective actuation of targetdevices from the second position to the first position.

In order for the target device to move from the second position to thefirst position, the device must already be in the second position, theline pressure in line C must be greater than that in line A and thecontrol valve associated with the target device must be in a positionconnecting the inlet port 14 of the control valve with the device port18 of the control valve. This set of conditions allows pressure fromline C to act on the target device while pressure is exhausted from thatdevice through line A. Target devices are in this way addressed one at atime as any device whose control valve is set in the position connectingthe inlet port 14 to the valve port 22 is dead headed at device port 18thereby hydraulically locking that device. In the system as illustrated,all but one of the control valves in the entire system is deadheaded.Thus for any given position of the system, only one device is operablebased upon a pressure up on line C. Because of this, selective controlof every individual device (or groups of devices if so configured on aparticular or each control valve) is achievable with the system hereof.As a worst case scenario on time required to operate a specific device,if the control valve of the target device is currently in the secondposition, a reset and then a pressure up sequence equal to the number ofpreceding valves is required to gain the required fluid connection for apressure-up on line C to actuate the target device from the second tothe first position.

The control valve and system described herein advantageously offersselective actuation between first and second positions of a particularone of a plurality of actuatable devices using solely three hydrauliccontrol lines at any given location within a wellbore or the otherinstallation requiring control of multiple devices using a limitednumber of control lines.

1. A control valve comprising: a housing; an inlet port at the housing;a device port at the housing; a valve port at the housing; and a spooldisposed at the housing, the spool initially connecting the inlet portto the device port and subsequently to a pressure event connecting theinlet port to the valve port.
 2. A control valve of claim 1 wherein thecontrol valve further comprises a reset port at the housing facilitativeof conditioning of the spool to connect the inlet port to the deviceport.
 3. An actuation system comprising: a plurality of control valves,each valve being addressable and conditionable to communicate with oneof a device and another control valve; and a plurality of devices eachin operable communication with one of the plurality of control valves.4. The actuation system of claim 3 wherein the valve is initiallyconditioned to communicate with an associated one of the plurality ofdevices and after being first addressed is automatically conditioned tocommunicate with another control valve.
 5. The actuation system of claim4 wherein the valve remains conditioned to communicate with the othervalve until a reset of the valve.
 6. The actuation system of claim 3including solely three control lines at any given point in the system.7. The actuation system of claim 6 wherein the lines include two linesfor pressure or bleed-off and one for reset.